Control apparatus for radio receivers



Feb. 10, 1942. A. w. PLENSLER CONTROL APPARATUS FOR RADIO RECEIVERS Flled Feb 27 1939 1 sires of the operator.

Patented Feb. 10, 1942 T oFFlcE-i RECEIVERS Alexander W. Plensler, Chicago, Ill., assignor to Belmont Radio Corporation,

poration of Illinois Chicago, Ill., acor- Application February .27, 1939, Serial N0. 258,609

11 Claims.

My invention relates in general to control apparatus for radio receivers and more in particular to manually operated automatic tuners for such receivers.

In automatic tuners for radio receivers some portion of the tuners is adjustable with'reference to another'portion so that the apparatus as a whole may be set to predetermined signal frequency positions, and such positions varied from time to time in accordance with the de- In many of the prior tuners rather complicated apparatus is required for the adju'stingand setting operation and in many instances independent tools, such as screw drivers and the like, are employed. These structures may be angularly adjusted upon the shaft indeare objectionable either from the standpoint of cost or from the fact that it is necessary to normally go to some trouble to find the adjusting tool.

An object of my invention is to provide a simplified tuner for manual operation which cart be set and reset to predetermined tuning positions by the active elements of the tuner itself.

A further object of my invention is to provide a tuner which can be set and reset-from the front of the apparatus without any extra tools.

A still further object of my invention is to provide a manually operated automatic tuner for a radio receiver having a plurality of control elements on a rotary shaft with each control element adapted to be set or reset to a predetermined position independently of the other control elements, and while maintaining such other control elements rigid on the rotary shaft.

One of the features of my invention is the provision of a combination selector or push-button unit and adjusting tool for use in varying the tuning positions of the tuner so thatno tools separate from the tuner elements themselves are required. l

Other objects and features of my invention will be apparent from the following description taken with the drawing, in which:

Fig. 1 is a fragmentary side elevation partly in section, of one complete tuner unit of my invention taken along the line |I. of Fig. 3. The unit is shown in normal idle position. i Fig. 2 is a similar view of such unit in operated position and taken along the line 22 of Fig. 3. v

Fig. 3 is a fragmentary top plan view of the tuner structure of my invention.

Fig. 4 is a detail View of the blank for the slidmovement of the carriage.

shaft.- Each control element includes a mounting portion supported on the shaft and having friction means therefor so that each control element pendent of the other control elements; Each control element is moved to a predetermined tuning position by means of a selector or pushbutton unit which includes'a linearly supported slidable carriage having a. portion for engagement with a corresponding control element, and a push-button member supported on such carriage for engagement by theoperator for linear The push-button member includes an elongated shank slidably supported upon the carriage with spring means intermediate the shank and such carriage to provide a yielding connection therebetween, and to normally maintain the push-button member in a retracted position with reference to the carriage. A socket portion is provided at the end of the shank for selected engagement with the friction means on the control element to adjust the friction means, andin turn prevent or permit the angular adjustment of the control element with reference to the rotary shaft. The push-button member is rotatably movable as well as linearly movable upon the carriage to accomplish the ad-.

justment of the friction means.

Although my invention may take numerous forms only two have been chosen for illustration. Referring tothe embodiment in Figs. 1 to 4, the tuner of my invention includes a frame I 0 having a rotary The rotary shaft is coupled or otherwise connected to a variable condenser I 2 or to any other desired resonance frequency changing means, such as a variable inductance. A plurality of control units are frictionally retained in adjacent relationship upon the rotary shaft, and

A able carriage in the apparatus of Figs. 1 to 3. 68

each control unit comprises a cam l3 with a collar orbushing I4 integral therewith or rigidly secured thereto, and a set screw l6 threadably secured in the bushing I4. The head I! ofthe set. screw I6 is somewhat conical nection with an adjusting tool as will be hereinafter explained.

shaft ll journalled therein.

in shape and DIOVIdGClWith a friction surface for ready conacter 22. The slidable carriage is supported at the front and rear as shown in Figs. 1 to .3, by means of-a pair of ,frame portions 23 and 24. A;

roller 26 is supported on the portion22 of the carriage for engagement withthe edge of the cam l3, and the carriage as a whole is supported in'frame portions 23 and in a position such that the roller moves on a straight line in alignment with the axis of the shaft The body portion of the carriage I6 is oflset so as to clear the shaft H and the. bushings l4 thereon as is evident from Figs. 1 and 2.

In forming the carriage |9 for the selector unit '|3 an car 21 is knocked out of the portion and a corresponding car 23 is bent at right angles thereto at the outer end of such portion 22. A

shank- 29 for the push-button member for each selector unit is slidably supported in apertures in the ears 21 and 23 so as to move along a line in axial alignment with the axis of the roller 26 and consequently the axis of the shaft A finger button 3| on one end of the shank 29 is positioned onthe outside of a radio receiver cabinet for engagement by an operator, and a socket portion33 is rigidly secured to the other end of the shank. The socket portion 33 has a cavity 34 therein for frictional engagement with the head I! on the set screw of the corresponding control element and when the push-button member with the shank 29 is in the position illustrated in Fig. 2, the socket 33 is in operative engagement with the head I! of the corresponding set screw. Although the roller 26 may be moved to the position shown in Fig. 2, the socket portion 33 is normally out of engagement with the head H by virtue of the pressure of the spring 36 supported on the shank 29 intermediate a washer 31 secured to the shank and the eat 21 on the carriage. The pressure of the spring 36 is such as to hold the shank 29 and button 3| thereon in a retracted position with reference to the carriage in the selector unit, such as shown in Fig. 1, although the carriage is moved to the position in Fig. 2 with the control element in a predetermined tuning position. As the operator continues to press on the button 3| against this spring pressure, the shank is moved linearly toward the set screw |6 until the cavity 34 is in engagement with the head H of the set screw. By rotating the button 3] to the right or to the left, the set screw is rotated in a similar direction for threadable adjustment to a position in frictional engagement with the shaft H or to a position out of frictional engagement with the shaft When the operator releases his finger from the button 3|, the spring 36 intermediate each carriage and the frame It, as at the frame portion 23, pulls the entire selector unit to an idle position such as shown in Fig. 1.

The operation of the selector unit to rotate a corresponding control element and thereby rotate the shaft therewith to a predetermined tuning position for the condenser I2 is apparent from the description above. In setting a cam l3 to an original predetermined position or resetting it to a subsequent predetermined position, the set screw i6 is loosened in the manner described above. When the socket portion 33 is in operative connection with the head ll of the set screw, the roller 26 is in set position with reference to the cam l3 as shown in Fig. 2. With the roller 26 retained in set position, the shaft H is rotated manually by any desired means (not shown) thereby moving the rotors of the variable condenser |2 to a desired tuning position. This position can be indicated bya dial and pointer in the usual manner. With the set screw l6 out of frictional engagement with the shaft II, and the cam l3 held by the roller 26 on the selector unit, the shaft rotates with reference to the cam |3. At the predetermined tuning position of the condenser l2, the socket 33 is brought into operative engagement with the head I! of the set screw, or possibly it might be in such engagement, and is rotated to threadably adjust the set screw |6 into frictional engagement with the shaft thereby frictionally locking the cam |3 on the shaft so that subsequent rotation of the cam l3 by its corresponding selector unit It will bring the cam and hence the shaft H to a predetermined angular position for tuning.

In order to retain the carriage l9 of the selector unit l3 in operated position,-with the roller 26 in the set-positioncavity of the cam l3 as shown in Fig. 2, a latch 4| is pivotally mounted in the frame [6 for the tuner. A spring 42 secured to the latch maintains a constant lateral pressure on the latch so as to hold it against the top edge of the selector carriage. When the carriage is in the position shown in Fig. 2 the latch is pulled into latching engagement with the shoulder 43 provided in a notch adjacent the end of the guide portion 2| of the carriage so as to retain such carriage in operated position. The latch is effective both during tuning and during a setting operation so that the cam l3 of a control unit is retained in tuned position irrespective of whether pressure is maintained on the pushbutton 3|. The push-button 3| may then be pushed inwardly at any time to effect an operative connection between the set screw I6 and socket portion 33 on the push-rod or shank 29. A-beveled configuration transversely of the latch as shown in Figs. 1 and 2 causes the latch to be pivoted by an inwardly slidable selector unit to raise the latch and release any previously latched selector unit.

A modification of my invention is illustrated in Fig. 5. In this modification a control unit is provided with a control member or cam l3" having a split collar or bushing l4 either integral therewith or rigidly secured thereto. The split collar or bushing includes a pair of integral offset ears 46 and 41 extending radially from such bushing and the shaft II. A set screw l6 with a somewhat conical corrugated head l'l is threadably secured in the two ears 46 and 41. The cam or control member I3 is rotated to, or held in a set position by means of a selector unit 48 including a linearly slidable carriage 49 supported in a pair of frame portions 5| and 52 in front of the control member. A roller 53 is rotatably mounted at the end of an extension on the carriage 49 and moves in alignment with theaxial center of the shaft The carriage 49 is moved linearly by a pushbutton 54 secured to one end of a push-rod or shank 56 slidably carried in a pair of cars 51 knocked out of the body portion of the carriage 49 in the forming-of the same. The ears 51 are offset from a line through the axial center of the shaft H and carry the shank 56 in such ofl'set position, but in alignment with the set screw IS in the bushing H of the control member. A

' cavity 58 in the end of the shank 56 is adapted for frictional engagement with the head ll of the set screw when the shank 56 is pushed inwardly against the pressure of a spring 59 carried on the shank intermediate an ear 5! and a washer 6|. The washer is rigidly secured on the shank 56, or at least locked against longitudinal movement thereon.

The operation of the modification is similar to that for the structure of Figs. 1 to 4, inclusive, described above, with the selector unit being slidable-to rotate the cam l3 to a set position, and the push-button 54 being slidable inwardly thereafter for meshing engagement between the cavity 58 and the set screw head IT. The pushbutton and connected shank member may then be rotated to adjust the screw it to friction or non-friction position.

From the above description it is apparent that I provide a simplified, sturdy, manually operated tuner for a radio receiver in which the tuning operations may be accomplished with a linear inward movement of the actuator portion of the tuner. The control portion of such unit may be set or reset to predetermined tuning positions by means carried directly on the tuner and having an operative function therein. The setting or resetting operation may be accomplished entirely from the front of the tuner.

The disclosures of this application are illustrative and the invention is not to be limited by them. In fact, if modifications or improvements are not at once obvious, they may be devised in the course of time to make additional use of the broad ideas taught and covered by this application. The claims are intended to point out novel features and not to limit the invention except as may be required by prior art.

I claim:

1. Tuning apparatus for a radio receiver including a rotary shaft, a control unit on such shaft adapted to be adjusted relative to said shaft and having friction adjusting means thereon for securing said unit in an adjusted position, means for moving said control unit to-predetermined tuning positions for said apparatus, means selectively connectible with said friction adjusting means to adjust the same to release said control unit from, or secure it to said shaft, and means on said means for moving said control unit slidably supporting said selectively connectible means thereon for linear movement into and out engagement with said shaft to permit or prevent movement of said control means with reference to said shaft, a selector carriageslidably mounted in said frame, an actuator, meansfor slidably mounting said actuator on said selector carriage, means operatively connecting said car.- riage and actuator in a manner so that the carriage is moved by movement of said actuator and yet said actuator is movable independently of the carriage for operative connection with said adjustable means, and with said actuator having a portion operatively connectible with said adjustable means.

4. Control apparatus fora radio receiver including a rotatable shaft, control means on said shaft including a control portion and a radially split bushing thereon, adjustable means in said bushing at the split portion for varying the frictional pressure thereof on said control shaft, movable selector unit comprising a carriage having an extension in alignment with the axial center of said control means for engagement with said control means, supporting an actuating member thereon, an actuating member carried on said supporting means, said actuating member being off-center with respect to said control portion but in alignment with said adjustable means, and said actuating member having an adjusting portion on one end thereof for selected operative connection with said adjustable means to adjust-the same and vary the frictional pressure intermediate said control means and the rotatable shaft.

5. A control device for controllable apparatus including a rotaryshaft, a control unit mounted on said shaft having means thereon for adjusting the friction between ,said control unit and said shaft, a selector unit for rotating said control unit including a slidable carriage, and a push member rotatably mounted on said carriage for moving said carriage into engagement with said control unit upon movement of said push of operative connection with said friction adv justing means.

2. Control apparatus for a radio receiver including a rotary shaft, a control unit supported on said shaft having threaded friction adjusting means thereon for varying the friction between such control unit and shaft to permit or prevent the movement of such control unit relative to said shaft, a selector unit for moving said control unit including a sliding carriage, means for supporting said carriage for linear slidable movement with reference to said control unit, said selector unit including a portion selectively mov- -able with reference to said carriage and operatively connected therewith to move said carriage to tuning position and selectively engage said friction adjusting means on said for adjusting such means.

3. A tuner for a radio receiver including a frame, a control shaft journalled in said frame, control means on said shaft including a control portion and a mounting portion, adjustable control unit means in said mounting portion for frictional 75 and a split mounting member, with said push member adapted to be moved relative to said carriage for operative connection with said friction adjusting means to rotate said friction adjusting means to change the adjustment thereof.

6. A control device for controllable apparatus including a rotary shaft, a control unit mounted on said shaft comprisinga control portion and a bushing portion thereon rigid with respect to such control portion, a set screw threadably secured in said bushing portion for frictional engagement with said shaft, a selector unit for rotating said control unit including a slidable carriage having an engaging portion in alignment with the axial center of said control 'unit for engaging said control portion, means for supporting said carriage for linear slidable movement, and a push member rotatably mounted on said carriage in alignment with the axial center of said control unit for moving' said carriage into engagement with said control unit upon movement of said push member, with said push member adapted for operative connection with said set screw to rotate the same to vary the frictional adjustment between the set screw and the rotary shaft. 7. A control device for controllable apparatus including a rotary shaft, a control unit mounted on said shaft comprising a control portion portion thereon rigid with respect to such control portion, threaded adjusting means in said varying the frictional pressure intermediate said means on said carriage forv split mounting portion for mounting portion and the rotary shaft. a seiector unit for rotating said control unit including a slidable carriage having an engaging portion in alignment with the axial center of said control unit for engaging said control portion,

means for supporting said carriage for linear slidable movement, and a push member rotatably mounted on said carriage in a position oi!- set from a line through the axial center of said control unit but in alignment with the adjusting means in said split mounting portion for moving said carriage into engagement with said control unit upon movement of said push memtrol unit to a predetermined tuning position,

said selector unit including a control unit driving portion and an actuator slidably mounted on said driving portion, and spring means for controlling the relative movement between said actuator and said control unit driving portion, said actuator having an adjusting portion at one end thereof, and said actuator being operable to move said driving portion into contact with said control unit and being operable to engage said adjusting portion with said friction adjusting means for changing the adjustment thereof.

9. A tuner for aradio receiver including a frame, a 'rotary control shaft mounted in said frame, a control unit supported on said shaft having friction adjusting means for varying the friction between such control unit and shaft to permit or prevent the movement of such control unit relative to said shaft, a selector carriage slidably mounted in said frame to contact and move said control unit to a predetermined tuning position, a push'member rotatably supported on said carriage and slidably movable relative thereto, and spring means for controlling the relative linear movement between said push member and selectorv carriage, initial linear movement of said push member acting to urge said selector carriage into contact with said control unit and later linear movement of said push member acting to engage said push rod with said friction adjusting means, said push memher being adapted for operative connection with said friction adjusting means to rotate the same to change the adjustment thereof.

10. In radio tuning mechanism having frame means, tuning control means including a carriage slidably supported in said frame means, a combination actuating and friction changing unit supported on said carria e for slidable relative movement, an adjustable control elementspaced from said combination unit, axis means supporting the control element and friction locking means operatively connected therewith, with said combination unit having. a push button on one end thereof and having a portion at the other end selectively engageable with a portion of the friction locking means, and with said combination unit being movable when in engagement with the portion of the friction locking means for moving the friction locking means to looking or unlocked position.

11. In radio tuning mechanism having frame means and control axis means, the-means for rotating said control axis means to a predetermined control position including a carriage slidably supportedin said frame means, a push unit supported on said carriage for slidable relative movement, a control element supported for adjustment relative to the control axis means, friction locking means operatively connected with said control element to lock said element in an adjusted position and having a head portion thereon, said push unit having an actuating portion at one end and having a portion at the other end engageable with the outside of said friction locking means 'head portion; with said friction locking means being rotatable by said push unit in the engaged position to control element looking position.

ALEXANDER W. PLENSLER. 

